Polycarbonate is a widely used polymeric material, due to its high level of heat resistance, dimensional stability, and ease of molding. To improve other performance properties such as chemical resistance and/or reduce the cost, other polymers, such as polyamides and polyesters can be blended with the polycarbonate.
US 2007/0066743 describes blends of polycarbonate and polyester using a vulcanizate along with an optional core/shell modifier and optional linear terpolymers to improve the impact resistance.
U.S. Pat. No. 7,015,261 discloses polyester and polycarbonate blends containing both a linear polyethylene having epoxy groups and an acrylic-based core/shell impact modifier. Acrylic core, core/shell impact modifiers provide less low temperature impact resistance than other types of impact modifiers.
U.S. Pat. No. 7,119,152 describes impact-modified polyesters having core/shell impact modifiers and ethylene epoxide copolymers. The polyester may contain up to 30 percent of polycarbonate or copolyetherester. The ratio of core/shell to ethylene epoxide copolymer is either a) 60-90/40-10 if 18-40% combined impact modifiers is present, and 60-75/40-25 when 2-18% of the combined impact modifiers are present.
It has now been found that blends of polycarbonate with higher levels of polyester and/or polyamide can provide good impact strength, when blended with the proper blend of core/shell and functional polyolefin impact modifiers.